Field of the Invention
The present invention relates to a digital television device for converting an analog video signal to a digital video signal and processing the digital video signal and, more particularly, to a color signal processing circuit therefor.
Along with the development of digital IC techniques, signal processing at the baseband which was conventionally subjected to analog processing, can be digitally performed in a television receiver.
A digital signal processing circuit is capable of high-precision and nondistorted processing. Stable operation with regard to changes in temperatures, deterioration over time and noise can also be achieved. The digital signal processing circuit can be coupled to a memory or a computer for easily performing multiscreen television processing, scanning rate conversion, still image processing and other special effects. The digital signal processing circuit can also be coupled to various different media signals.
In a digital television system, in the same manner as in the conventional analog television system, automatic chroma control (ACC), color saturation control, hue control, chrominance signal demodulation and matrix operation are required. Many multipliers are required for this signal processing. As is well known to those skilled in the art, multiplier circuits are large. For example, in a multiplier network for multiplying data of 8.times.8 bits, about 1,000 gates are required. The large size of the multiplier is a critical problem in preparing a digital video signal processing IC.
Another problem is that a great number of circuits are required for the matrix operation. When the matrix operation is performed by a digital circuit, external R, G, B signals can be easily handled. One advantage, however, is that many additional components required for the analog matrix circuit can be omitted. There is a strong demand for a decrease in the number of components in the matrix circuit.